The Physiology Core will provide critical support for assessment of function through four aims. Aim 1: Enhance and extend the quality and scope of the individual research projects: The Core will provide and facilitate application of methods and approaches that are not within the expertise of individual investigators but can address hypotheses in their studies. The most common assessment is of auditory brain stem response (ABR) with more in-depth measures, e.g. otoacoustic emissions, efferent reflex, round window noise, cochlear microphonics, cochlear whole-nerve action potentials and endolymphatic potential also available. The Core also develops conditions for and coordinates noise exposures of animals. Aim 2: Improve the efficiency and productivity of ongoing research within the user group: The Core will provide centralized, well maintained equipment and facilities and shared resources for various physiological measurements. It will also provide training of students, fellows and staff in the basic methods (for example ABR), avoiding pitfalls and facilitating accurate interpretation of results. Expert staff will perform and/or assist in measurement of complex physiological functions. Aim 3: Develop methods and approaches to meet current and anticipated user needs: The Core will work with individual investigators to modify and develop applications and contribute to experimental design to select most appropriate physiological parameters. The Core will now offer a new screen to test basic vestibular function developed by Dr. King (consultant) to meet needs of our user base. Aim 4: Provide education, develop interactions and new collaborations: The Core will continue to train students, fellows and staff in routine procedures and facilitate adoption of new ones. Meetings with faculty, students and staff provide a forum for education and information on novel and advanced methodologies as do presentations at the regularly scheduled larger group meetings of Core A (Scientific Synergy Core). The Physiology Core also aids in the interpretation and the preparation of results for publications. Together with the Cell and Molecular Biology Core (Core C), the Physiology Core provides an essential link of genetic, molecular and biochemical data to structure and function.